If you enjoyed it for that reason, I'd recommend "Assignment in Eternity", also by published by Baen. It too is very early Heinlein (a collection of a couple of novellas and a couple of long-ish short stories).

I've certainly read that one. I think I've read all Heinlein's books at some time or other.

But I will, no doubt, pick up that book when it makes it into another Baen monthly bundle in the future, hopefully the July 2013 bundle.